Coil spring for bed mattress having means for preventing frictional noise

ABSTRACT

A coil spring for a bed mattress. At least one of contact wiring portions  16 - 5  and  16 - 5 ′ of the upper and lower exposed wiring portions  16  and  16 ′ which abut to the end wiring portions  14  while the upper and lower exposed wiring portion  16, 16 ′ are being compressed has a contact surface A which is in contact with one corresponding end wiring portion of the end wiring portions  14 , whereby frictional noise between the exposed wiring portion  16, 16 ′ and the end wiring portion  14  is prevented. It is possible to consequently remove friction that is created due to contact between the exposed wiring portion and the end wiring portion while the exposed portion is being compressed, thereby preventing noise. The exposed wiring portion and the body wiring portion move only upward and downward without being displaced or deformed in the lateral direction, thereby increasing longevity.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priorities from Korean Patent ApplicationNumber 10-2013-33188 filed on Mar. 28 2013 and Korean Patent ApplicationNumber 10-2013-38366 filed on Apr. 9, 2013, claiming priority fromKorean Patent Application Number 10-2013-33188 filed on Mar. 28 2013,the entire contents of which are incorporated herein for all purposes bythis reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a coil spring for a bed mattress havingan exposed wiring portion which is formed on the coil spring for a bedmattress and works together with a spring body to absorb an externalload, and more particularly, to a coil spring for a bed mattress havingmeans for preventing frictional noise which can prevent the noise thatis created by the friction between an exposed wiring portion and asurrounding wiring portion while the exposed wiring portion is beingcompressed.

2. Description of Related Art

In General, a bed mattress is an instrument for sleeping which providesa cushion or a buffering force using cushion members which arerespectively stacked on the upper surface and the undersurface of aspring assembly. The spring assembly includes a plurality of coilsprings which are provided between upper and lower frames inside the bedmattress and are regularly disposed at preset distances in the columnand row directions.

In addition, “exposed wire springs” were developed and have been used asmeans for enhancing the cushioning and buffering force of the bedmattress. The exposed wire springs include coil springs which aredisposed in the top-bottom direction between the upper and lower edgemembers such that the coil springs protrude above the upper edge member.

For instance, as shown in FIG. 1, a spring assembly 1 includes upper andlower edge members 20 and 20′, coil springs 10 which are arranged in rowand column directions R and C within the space between the upper edgemember 20 and the lower edge member 20′, and helical coils 30 which arespirally engaged with the coil springs 10 in the row direction R.

In addition, as shown in FIG. 2, each of the coil springs 10 includes abody wiring portion 12 situated in a space between the upper edge member20 and the lower edge member 20′, end wiring portions 14 provided onboth ends of the body wiring portion 12 so as to be engaged with theupper and lower edge members 20 and 20′, and an exposed wiring portion16 extending from one of the end wiring portions 14 so as to be exposedfrom the edge member 20.

Here, in the case of attempting to set the spring assembly 1, when thehelical coils 30 are engaged in the state in which the coil springs 10are set at preset distances from each other between the edge members 20and 20′, the exposed wiring portions 16 are set such that they protrudeabove the upper edge member 20 or below the lower edge member 20′.

In addition, when the spring assembly 1 is applied to a bed mattress,the exposed wiring portions 16 absorbs shock when a small load isapplied in response to, for example, rolling over of a mattress user,and the body wiring portions 12 absorb shock when a large load isapplied from the mattress user.

The coil springs 12 advantageously increase the comfort and convenienceof the user since the exposed wiring portions 16 and the body wiringportions 12 properly distribute the shock-absorbing function in responseto variation in the load applied to the bed mattress. However, the coilsprings 12 have at least the following problems.

First, as shown in FIG. 3, in the process in which the coil spring 10 iscompressed at the moment that the bed mattress is subjected to a load, acontact wiring portion 16-5 of the exposed wiring portion 16 abuts tothe end wiring portion 14 which is positioned below while moving down.This consequently creates noise due to contact between the exposedwiring portion 16 and the end wiring portion 14.

Second, when a large load is applied to the bed mattress, the exposedwiring portion 16 of the spring assembly is compressed, andconcurrently, the body wiring portion 12 is compressed at a high speed.Rapid compression of the exposed wiring portion 16 increases thefriction between the exposed wiring portion 16 and the end wiringportion 14, thereby creating frictional noise.

In addition, Korean Patent No. 10-0444347 (U.S. Pat. No. 6,983,503)disclosed means for preventing frictional noise in the coil spring 10.The means for preventing frictional noise includes foaming the exposedwiring portions. Foaming of the exposed wiring portions of the coilspring 10 leads to an advantage in that the interference between theupper and/or lower edge members and the exposed wiring portions of thecoil spring is completely prevented, thereby preventing frictionalnoise. However, there are drawbacks in that the process of foaming theexposed wiring portions is added, a cost for purchasing equipment whichseals the exposed wiring portions by foaming increases, and costs forthe material and the process for the foaming and sealing increase.

Accordingly, solutions for preventing stress due to frictional noisebetween the exposed wiring portions 16 and the end wiring portions 14while the bed mattress is being used and for increasing the longevity ofthe coil spring are urgently required

The information disclosed in the Background of the Invention section isprovided only for better understanding of the background of theinvention, and should not be taken as an acknowledgment or any form ofsuggestion that this information forms a prior art that would already beknown to a person skilled in the art.

RELATED ART DOCUMENT

-   Patent Document 1: Korean Patent No. 10-0444347 (patented Apr. 30,    2004)-   Patent Document 2: U.S. Pat. No. 6,983,503 (patented Jan. 10, 2006)

BRIEF SUMMARY OF THE INVENTION

Various aspects of the present invention provide a coil spring for a bedmattress having means for preventing frictional noise which can preventthe noise that is created due to the friction between an exposed wireportion which protrudes upward or downward from a spring assembly and asurrounding wiring portion while the exposed wiring portion is beingcompressed.

In an aspect of the present invention, provided is a coil spring for abed mattress having means for preventing frictional noise which includesa body wiring portion situated in the space between an upper edge memberand a lower edge member, an end wiring portion provided on both ends ofthe body wiring portion and set within a range in which the upper andlower edge members are disposed, and means for preventing frictionalnoise which include at least one of an upper exposed wiring portionextending from the end wiring portion so as to be exposed from the upperedge member and a lower exposed wiring portion extending from the endwiring portion so as to be exposed from the lower edge member. At leastone of contact wiring portions of the upper and lower exposed wiringportions which abut to the end wiring portions while the upper and lowerexposed wiring portion are being compressed has a contact surface whichis in contact with one corresponding end wiring portion of the endwiring portions, whereby frictional noise between the exposed wiringportion and the end wiring portion is prevented.

In another aspect of the present invention, provided is a coil springfor a bed mattress having means for preventing frictional noise whichincludes a body wiring portion situated in the space between an upperedge member and a lower edge member, an end wiring portion provided onboth ends of the body wiring portion and set within a range in which theupper and lower edge members are disposed, and means for preventingfrictional noise which include at least one of an upper exposed wiringportion extending from the end wiring portion so as to be exposed fromthe upper edge member and a lower exposed wiring portion extending fromthe end wiring portion so as to be exposed from the lower edge member.The coil spring further includes at least one rigid support end which isprovided on the body wiring portion or the upper or lower exposed wiringportion so as to absorb a compressive load. At least one of contactwiring portions of the upper and lower exposed wiring portions whichabut to the end wiring portions while the upper and lower exposed wiringportion are being compressed has a contact surface which is in contactwith one corresponding end wiring portion of the end wiring portions,whereby frictional noise between the exposed wiring portion and the endwiring portion is prevented.

As set forth above, the present invention has at minimum the followingeffects.

First, since the coil spring is provided with the contact surface wherethe exposed wiring portion abuts to the end wiring portion such that thecontact state is maintained or the contact point, where the exposedwiring portion abuts to the end wiring portion, is fixed, it is possibleto remove friction that is created due to contact between the exposedwiring portion and the end wiring portion while the exposed portion isbeing compressed, thereby preventing noise.

Second, since the coil spring is provided with the contact surface wherethe exposed wiring portion abuts to the end wiring portion such that thecontact state is maintained or the contact point where the exposedwiring portion abuts to the end wiring portion is fixed, the exposedwiring portion and the body wiring portion move only upward and downwardwithout being displaced or deformed in the lateral direction, therebyincreasing longevity.

Third, in the state where frictional noise between the exposed wiringportion and the end wiring portion of the coil spring is minimized,small and large loads applied to the bed mattress are discriminated anda suitable level of buffering force is provided, thereby improving thequality of a product.

Fourth, the process of foaming the exposed wiring portion, which wasproposed in Korean Patent No. 10-0444347 and U.S. Pat. No. 6,983,503 asmeans for preventing frictional noise in the coil spring, becomesunnecessary. It is possible to preclude equipment which seals theexposed wiring portion and the sealing process as well as reduce theprice for purchasing that equipment and the cost for the process,thereby improving productivity.

Fifth, the coil springs were provided with the contact surfaces, at eachof which the exposed wiring portion and the end wiring portion abuttedto and stayed in contact with each other, and were applied to theabove-mentioned bed mattress, and frictional noise was measured.Consequently, it was noted that frictional noise was significantlyreduced as presented in the results in the “Certificate of Analysis”validated by the internationally recognized testing laboratory.

Here, among test samples presented in the “Test Report on Measurement ofNoise in Spring Plate” attached to the “Certificate of Analysis,”Samples A-1 and B-1 indicate bed mattresses to which the coil springshown in FIG. 1 to 3 were applied, Samples A-2, B-2 and C-2 indicate bedmattresses to which the coil spring proposed in Korean Patent No.10-0444347 was applied, and Samples A-3, B-3 and C-3 indicate bedmattresses to which the coil springs shown in FIG. 4 to FIG. 13 wereapplied.

The methods and apparatuses of the present invention have other featuresand advantages which will be apparent from, or are set forth in greaterdetail in the accompanying drawings, which are incorporated herein, andin the following Detailed Description of the Invention, which togetherserve to explain certain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall perspective view showing a spring assembly of therelated art;

FIG. 2 is a cross-sectional view showing the spring assembly of therelated art;

FIG. 3 is a cross-sectional view illustrating creation of noise from thecoil spring of the related art;

FIG. 4A to FIG. 4D show applications of a spring assembly of the presentinvention, in which FIG. 4A is a cross-sectional view showing anapplication of a spring assembly of the present invention, FIG. 4B is aperspective view showing the state in which offset springs are disposed,FIG. 4C is a perspective view showing the state in which round springsare disposed, and FIG. 4D is a perspective view in which round offsetsprings are disposed;

FIG. 5 is a cross-sectional and perspective view showing a firstembodiment of the coil spring according to one application of thepresent invention;

FIG. 6 is a cross-sectional and perspective view showing a secondembodiment of the coil spring according to one application of thepresent invention;

FIG. 7 is a cross-sectional and perspective view showing a thirdembodiment of the coil spring according to one application of thepresent invention;

FIG. 8A to FIG. 8D show other applications of a spring assembly of thepresent invention, in which FIG. 8A is a cross-sectional view showing anapplication of a spring assembly of the present invention, FIG. 8B is aperspective view showing the state in which offset springs are disposed,FIG. 8C is a perspective view showing the state in which round springsare disposed, and FIG. 8D is a perspective view in which round offsetsprings are disposed;

FIG. 9 is a cross-sectional and perspective view showing a fourthembodiment of the coil spring according to another application of thepresent invention;

FIG. 10 is a cross-sectional and perspective view a fifth embodiment ofthe coil spring according to another application of the presentinvention;

FIG. 11 is a cross-sectional and perspective view showing a sixthembodiment of the coil spring according to another application of thepresent invention;

FIG. 12 is a cross-sectional and perspective view showing a seventhembodiment of the coil spring according to another application of thepresent invention; and

FIG. 13 is a cross-sectional and perspective view showing an eighthembodiment of the coil spring according to another application of thepresent invention.

DETAILED DESCRIPTION OF TEE INVENTION

Reference will now be made in detail to various embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings and described below.

First, among components of the present invention, since an upper edgemember 20, a lower edge member 20′ and helical coils 30 havesubstantially the same function as those shown in FIG. 1 to FIG. 3, theywill be described with reference to the same reference numerals.

In addition, in the accompanying drawings of the present invention, FIG.4 to FIG. 7 show coil springs 10 which do not include a rigid supportend 18, and FIG. 8 to 13 show coils springs 10 which include at leastone rigid support end 18.

In addition, FIG. 4 to FIG. 13 of the present invention show the statein which end wiring portions 14 are in contact with exposed wiringportions 16 and 16′.

A description will be given below of first to eighth embodiments of thepresent invention.

Embodiment 1

FIG. 5 is a cross-sectional and perspective view showing a firstembodiment of the coil spring of the spring assembly according to thepresent invention.

This embodiment of the present invention provides a coil spring for abed mattress having means for preventing frictional noise which includesa body wiring portion 12 situated in the space between the upper edgemember 20 and the lower edge member 20′, the end wiring portions 14provided on both ends of the body wiring portion 12 and set within arange in which the upper and lower edge members 20 and 20′ are disposed,and at least one of the upper exposed wiring portion 16 extending fromthe end wiring portion 14 so as to be exposed from the upper edge member20 and the lower exposed wiring portion 16′ extending from the endwiring portion 14 so as to be exposed from the lower edge member 20′.

Here, contact wiring portions 16-5 and 16-5′ which abut to the endwiring portions 14 while the upper and lower exposed wiring portions 16and 16′ are being compressed have contact surfaces A which are set incontact with the end wiring portions 14, whereby frictional noisebetween the upper and lower exposed wiring portions 16 and 16′ and theend wiring portions 14 is prevented.

First, since the upper and lower edge members 20 and 20′ and the helicalcoils 30 are well-known in the art, detailed descriptions thereof willbe omitted. Disclosure will be limited to the coil springs 10 which aresequentially disposed between the upper and lower edge members 20 and20′.

In addition, the coil spring 10 according to this embodiment indicatesthe spring having the upper exposed wiring portion 16 and the lowerexposed wiring portion 16′ which are respectively formed on the upperend and the lower end of the body wiring portion 12. In particular, thecoil spring 10 is configured such that the contact wiring portion 16-5of the upper exposed wiring portion 16 abuts to one of the end wiringportions 14 and the contact wiring portion 16-5′ of the lower exposedwiring portion 16′ abuts to the other one of the end wiring portions 14.

Since the contact wiring portions 16-5 and 16-5′ are provided with thecontact surfaces A having a preset length which stay in contact with theend wiring portions 14, the contact wiring portions 16-5 and 16-5′ areset so as to stay in contact with the end wiring portions 14.

In addition, the body wiring portion 12 indicates the wiring portionwhich is situated in the vertical direction in the space between theupper and lower edge members 20 and 20′ so as to support the load of thebed mattress. The wiring portion can have a variety of shapes includinga double-headed drum, and such a variety of shapes belongs to thetechnical scope of the present invention.

Furthermore, the end wiring portions 14 indicate the wiring portionswhich are positioned within the range in which the edge members 20 and20′ are arranged when the end wiring portions are respectively formed onboth ends of the body wiring portion 12 in the horizontal direction. Theend wiring portions 14 are fixed to the edge members 20 and 20′ viafixing pins or helical coils.

In addition, the exposed wiring portions 16 and 16′ indicate the wiringportions which further extend from the end wiring portions 14 and arewound such that their diameter is smaller than the diameter of the bodywiring portion 12. The exposed wiring portions 16 and 16′ arecharacterized in that they are compressed with a load smaller than thebody wiring portion 12.

Embodiment 2

FIG. 6 is a cross-sectional and perspective view showing a secondembodiment of the coil spring of the spring assembly according to thepresent invention.

This embodiment of the present invention provides a coil spring for abed mattress having means for preventing frictional noise which includesa body wiring portion 12 situated in a space between the upper edgemember 20 and the lower edge member 20′, the end wiring portions 14provided on both ends of the body wiring portion 12 and set within arange in which the upper and lower edge members 20 and 20′ are disposed,and the upper exposed wiring portion 16 extending from one of the endwiring portions 14 so as to be exposed from the upper edge member 20.Here, a contact wiring portion 16-5 which abuts to one of the end wiringportions 14 while the upper exposed wiring portion 16 is beingcompressed has a contact surface A which is in contact with that endwiring portion 14, whereby frictional noise between the upper exposedwiring portion 16 and that end wiring portion 14 is essentiallyprevented.

First, since the upper and lower edge members 20 and 20′ and the helicalcoils 30 are well-known in the art, detailed descriptions thereof willbe omitted. Disclosure will be limited to the coil springs 10 which aresequentially disposed between the upper and lower edge members 20 and20′.

In addition, the coil spring 10 according to this embodiment indicatesthe spring having the upper exposed wiring portion 16 which is formed onthe upper end of the body wiring portion 12. In particular, the coilspring 10 is configured such that the contact wiring portion 16-5 of theupper exposed wiring portion 16 abuts to one of the end wiring portions14.

Since the contact wiring portion 16-5 is provided with the contactsurface A having a preset length which stays in contact to one of theend wiring portions 14, the contact wiring portion 16-5 is set so as tostay in contact with that end wiring portion 14.

In addition, the body wiring portion 12 indicates the wiring portionwhich is situated in the vertical direction in the space between theupper and lower edge members 20 and 20′ so as to support the load of thebed mattress. The wiring portion can have a variety of shapes includinga double-headed drum, and such a variety of shapes belongs to thetechnical scope of the present invention.

Furthermore, the end wiring portions 14 indicate the wiring portionswhich are positioned within the range in which the edge members 20 and20′ are arranged when the end wiring portions are respectively formed onboth ends of the body wiring portion 12 in the horizontal direction. Theend wiring portions 14 are fixed to the edge members 20 and 20′ viafixing pins or helical coils.

In addition, the upper exposed wiring portion 16 indicates the wiringportion which further extends from one of the end wiring portions 14 andis wound such that its diameter is smaller than the diameter of the bodywiring portion 12. The upper exposed wiring portion 16 is characterizedin that it is compressed with a load smaller than the body wiringportion 12.

Embodiment 3

FIG. 7 is a cross-sectional and perspective view showing a thirdembodiment of the coil spring of the spring assembly according to thepresent invention.

This embodiment of the present invention provides a coil spring for abed mattress having means for preventing frictional noise which includesa body wiring portion 12 situated in a space between the upper edgemember 20 and the lower edge member 20′, the end wiring portions 14provided on both ends of the body wiring portion 12 and set within arange in which the upper and lower edge members 20 and 20′ are disposed,and the lower exposed wiring portion 16′ extending from one of the endwiring portions 14 so as to be exposed from the lower edge member 20′.Here, a contact wiring portion 16-5′ which abuts to one of the endwiring portions 14 while the lower exposed wiring portion 16′ is beingcompressed has a contact surface A which is in contact with that endwiring portion 14, whereby frictional noise between the lower exposedwiring portion 16′ and that end wiring portion 14 is essentiallyprevented.

-   -   First, since the upper and lower edge members 20 and 20′ and the        helical coils 30 are well-known in the art, detailed 20;        descriptions thereof will be omitted. Disclosure will be limited        to the coil springs 10 which are sequentially disposed between        the upper and lower edge members 20 and 20′.

In addition, the coil spring 10 according to this embodiment indicatesthe spring having the lower exposed wiring portion 16′ which is formedon the lower end of the body wiring portion 12. In particular, the coilspring 10 is configured such that the contact wiring portion 16-5′ ofthe lower exposed wiring portion 16′ abuts to one of the end wiringportions 14.

Since the contact wiring portion 16-5′ is provided with the contactsurface A having a preset length which stays in contact to one of theend wiring portions 14, the contact wiring portion 16-5′ is set so as tostay in contact with that end wiring portion 14.

In addition, the body wiring portion 12 indicates the wiring portionwhich is situated in the vertical direction in the space between theupper and lower edge members 20 and 20′ so as to support the load of thebed mattress. The wiring portion can have a variety of shapes includinga double-headed drum, and such a variety of shapes belongs to thetechnical scope of the present invention.

Furthermore, the end wiring portions 14 indicate the wiring portionswhich are positioned within the range in which the edge members 20 and20′ are arranged when the end wiring portions are respectively formed onboth ends of the body wiring portion 12 in the horizontal direction. Theend wiring portions 14 are fixed to the edge members 20 and 20′ viafixing pins or helical coils.

In addition, the lower exposed wiring portion 16′ indicates the wiringportion which further extends from one of the end wiring portions 14 andis wound such that its diameter is smaller than the diameter of the bodywiring portion 12. The lower exposed wiring portion 16′ is characterizedin that it is compressed with a load smaller than the body wiringportion 12.

Embodiment 4 to Embodiment 6

FIG. 9 to FIG. 11 are cross-sectional and perspective views showingfourth to sixth embodiments of the coil spring of the spring assemblyaccording to the present invention.

This embodiment of the present invention provides a coil spring for abed mattress having means for preventing frictional noise which includesa body wiring portion 12 situated in a space between the upper edgemember 20 and the lower edge member 20′, the end wiring portions 14provided on both ends of the body wiring portion 12 and set within arange in which the upper and lower edge members 20 and 20′ are disposed,and at least one of the upper exposed wiring portion 16 extending fromthe end wiring portion 14 so as to be exposed from the upper edge member20 and the lower exposed wiring portion 16′ extending from the endwiring portion 14 so as to be exposed from the lower edge member 20′.The coil spring further includes one rigid support end 18 which isprovided on the body wiring portion 12 or the upper or lower exposedwiring portions 16 and 16′ so as to absorb a compressive load.Alternatively, a plurality of rigid support ends can be provided on thebody wiring portion 12 or the upper or lower exposed wiring portions 16and 16′. Contact wiring portions 16-5 and 16-5′ which abut to the endwiring portions 14 while the upper and lower exposed wiring portions 16and 16′ are being compressed have contact surfaces A which are set incontact with the end wiring portions 14, whereby frictional noisebetween the upper and lower exposed wiring portions 16 and 16′ and theend wiring portions 14 is prevented.

First, since the upper and lower edge members 20 and 20′ and the helicalcoils 30 are well-known in the art, detailed descriptions thereof willbe omitted. Disclosure will be limited to the coil springs 10 which aresequentially disposed between the upper and lower edge members 20 and20′.

In addition, the coil spring 10 according to this embodiment indicatesthe spring having the upper exposed wiring portion 16 and the lowerexposed wiring portion 16′ which are respectively formed on the upperend and the lower end of the body wiring portion 12. In particular, thecoil spring 10 is configured such that the contact wiring portion 16-5of the upper exposed wiring portion 16 abuts to one of the end wiringportions 14 and the contact wiring portion 16-5′ of the lower exposedwiring portion 16′ abuts to the other one of the end wiring portions 14.

Since the contact wiring portions 16-5 and 16-5′ are provided with thecontact surfaces A having a preset length which stay in contact with theend wiring portions 14, the contact wiring portions 16-5 and 16-5′ areset so as to stay in contact with the end wiring portions 14.

In addition, the body wiring portion 12 indicates the wiring portionwhich is situated in the vertical direction in the space between theupper and lower edge members 20 and 20′ so as to support the load of abed mattress. The wiring portion can have a variety of shapes includinga double-headed drum, and such a variety of shapes belongs to thetechnical scope of the present invention.

Furthermore, the end wiring portions 14 indicate the wiring portionswhich are positioned within the range in which the edge members 20 and20′ are arranged when the end wiring portions are respectively formed onboth ends of the body wiring portion 12 in the horizontal direction. Theend wiring portions 14 are fixed to the edge members 20 and 20′ viafixing pins or helical coils.

In addition, the exposed wiring portions 16 and 16′ indicate the wiringportions which further extend from the end wiring portions 14 and arewound such that their diameter is smaller than the diameter of the bodywiring portion 12. The exposed wiring portions 16 and 16′ arecharacterized in that they are compressed with a load smaller than thebody wiring portion 12.

Furthermore, when a small load is applied to the bed mattress, the rigidsupport end 18 absorbs the compressive load using the exposed wiringportions 16 and 16′. When a large load is applied to the bed mattress,the rigid support end 18 prevents the load of the exposed wiringportions 16 and 16′ from being transferred to the body wiring portion12.

Although one rigid support end 18 can be provided on the upper or lowerportion of the body wiring portion 12, a plurality of rigid support endscan be provided at preset intervals on the body wiring portion 12. Thisconfiguration of course belongs to the technical scope of the presentinvention.

In addition, when the rigid support end 18 is formed on at least one ofthe exposed wiring portions 16 and 16′, this configuration of coursebelongs to the technical scope of the present invention.

In this case, the exposed wiring portions 16 and 16′ can of course beimplemented as a variety of shapes of wiring portions including adouble-headed drum.

Furthermore, it is preferred that the rigid support end 18 be formed ata right angle or an acute angle with respect to the end wiring portion14 or the horizontal plane.

Embodiment 7

FIG. 12 is a cross-sectional and perspective view showing a seventhembodiment of the coil spring according to the present invention.

This embodiment of the present invention provides a coil spring for abed mattress having means for preventing frictional noise which includesa body wiring portion 12 situated in a space between the upper edgemember 20 and the lower edge member 20′, the end wiring portions 14provided on both ends of the body wiring portion 12 and set within arange in which the upper and lower edge members 20 and 20′ are disposed,and at least the upper exposed wiring portion 16 extending from the endwiring portion 14 so as to be exposed from the upper edge member 20. Thecoil spring further includes at least one rigid support end 18 which isprovided on the body wiring portion 12 or the upper or lower exposedwiring portion 16 so as to absorb a compressive load. A contact wiringportion 16-5 which abuts to the end wiring portions 14 while the upperand lower exposed wiring portion 16 is being compressed has a contactsurface A which is in contact with the end wiring portion 14, wherebyfrictional noise between the upper exposed wiring portion 16 and the endwiring portions 14 is essentially prevented.

First, since the upper and lower edge members 20 and 20′ and the helicalcoils 30 are well-known in the art, detailed descriptions thereof willbe omitted. Disclosure will be limited to the coil springs 10 which aresequentially disposed between the upper and lower edge members 20 and20′.

In addition, the coil spring 10 according to this embodiment indicatesthe spring having the upper exposed wiring portion 16 which is formed onthe upper end of the body wiring portion 12. In particular, the coilspring 10 is set such that the contact wiring portion 16-5 of the upperexposed wiring portion 16 stays in contact to one of the end wiringportions 14.

Since the contact wiring portion 16-5 is provided with the contactsurface A having a preset length which stays in contact to one of theend wiring portions 14, the contact wiring portion 16-5 is set so as tostay in contact with that end wiring portion 14.

In addition, the body wiring portion 12 indicates the wiring portionwhich is situated in the vertical direction in the space between theupper and lower edge members 20 and 20′ so as to support the load of thebed mattress. The wiring portion can have a variety of shapes includinga double-headed drum, and such a variety of shapes belongs to thetechnical scope of the present invention.

Furthermore, the end wiring portions 14 indicate the wiring portionswhich are positioned within the range in which the edge members 20 and20′ are arranged when the end wiring portions are respectively formed onboth ends of the body wiring portion 12 in the horizontal direction. Theend wiring portions 14 are fixed to the edge members 20 and 20′ viafixing pins or helical coils.

In addition, the upper exposed wiring portion 16 indicates the wiringportion which further extends from one of the end wiring portions 14 andis wound such that its diameter is smaller than the diameter of the bodywiring portion 12. The upper exposed wiring portion 16 is characterizedin that it is compressed with a load smaller than the body wiringportion 12.

Furthermore, when a small load is applied to the bed mattress, the rigidsupport end 18 absorbs the compressive load using the upper exposedwiring portion 16. When a large load is applied to the bed mattress, therigid support end 18 prevents the load of the upper exposed wiringportion 16 from being transferred to the body wiring portion 12.

Although one rigid support end 18 can be provided on the upper or lowerportion of the body wiring portion 12, a plurality of rigid support endscan be provided at preset intervals on the body wiring portion 12. Thisconfiguration of course belongs to the technical scope of the presentinvention.

In addition, when the rigid support end 18 is formed on at least one ofthe upper exposed wiring portion 16, this configuration of coursebelongs to the technical scope of the present invention.

In this case, the upper exposed wiring portion 16 can be implemented asa variety of shapes of wiring portions including a double-headed drum.

Furthermore, it is preferred that the rigid support end 18 be formed ata right angle or an acute angle with respect to the end wiring portion14 or the horizontal plane.

Embodiment 8

FIG. 13 is a cross-sectional and perspective view showing an eighthembodiment of the coil spring of the spring assembly according toanother application of the present invention.

This embodiment of the present invention provides a coil spring for abed mattress having means for preventing frictional noise which includesa body wiring portion 12 situated in a space between the upper edgemember 20 and the lower edge member 20′, the end wiring portions 14provided on both ends of the body wiring portion 12 and set within arange in which the upper and lower edge members 20 and 20′ are disposed,and at least the lower exposed wiring portion 16′ extending from the endwiring portion 14 so as to be exposed from the upper edge member 20. Thecoil spring further includes at least one rigid support end 18 which isprovided on the body wiring portion 12 or the upper or lower exposedwiring portion 16′ so as to absorb a compressive load. A contact wiringportion 16-5 which abuts to the end wiring portions 14 while the upperand lower exposed wiring portion 16 is being compressed has a contactsurface A which is in contact with the end wiring portion 14, wherebyfrictional noise between the lower exposed wiring portion 16′ and theend wiring portions 14 is essentially prevented.

First, since the upper and lower edge members 20 and 20′ and the helicalcoils 30 are well-known in the art, detailed descriptions thereof willbe omitted. Disclosure will be limited to the coil springs 10 which aresequentially disposed between the upper and lower edge members 20 and20′.

In addition, the coil spring 10 according to this embodiment indicatesthe spring having the lower exposed wiring portion 16′ which is formedon the lower end of the body wiring portion 12. In particular, the coilspring 10 is configured such that the contact wiring portion 16-5′ ofthe lower exposed wiring portion 16 stays in contact with one of the endwiring portions 14.

Since the contact wiring portion 16-5′ is provided with the contactsurface A having a preset length which stays in contact with one of theend wiring portions 14, the contact wiring portion 16-5′ is set so as tostay in contact with that end wiring portion 14.

In addition, the body wiring portion 12 indicates the wiring portionwhich is situated in the vertical direction in the space between theupper and lower edge members 20 and 20′ so as to support the load of thebed mattress. The wiring portion can have a variety of shapes includinga double-headed drum, and such a variety of shapes belongs to thetechnical scope of the present invention.

Furthermore, the end wiring portions 14 indicate the wiring portionswhich are positioned within the range in which the edge members 20 and20′ are arranged when the end wiring portions are respectively formed onboth ends of the body wiring portion 12 in the horizontal direction. Theend wiring portions 14 are fixed to the edge members 20 and 20′ viafixing pins or helical coils.

In addition, the lower exposed wiring portion 16′ indicates the wiringportion which further extends from one of the end wiring portions 14 andis wound such that its diameter is smaller than the diameter of the bodywiring portion 12. The lower exposed wiring portion 16′ is characterizedin that it is compressed with a load smaller than the body wiringportion 12.

Furthermore, when a small load is applied to the bed mattress, the rigidsupport end 18 absorbs the compressive load using the lower exposedwiring portion 16′. When a large load is applied to the bed mattress,the rigid support end 18 prevents the load of the lower exposed wiringportion 16′ from being transferred to the body wiring portion 12.

Although one rigid support end 18 can be provided on the upper or lowerportion of the body wiring portion 12, a plurality of rigid support endscan be provided at preset intervals on the body wiring portion 12. Thisconfiguration of course belongs to the technical scope of the presentinvention.

In addition, when the rigid support end 18 is formed on at least one ofthe lower exposed wiring portion 16′, this configuration of coursebelongs to the technical scope of the present invention.

In this case, the lower exposed wiring portion 16′ can of course beimplemented as a variety of shapes of wiring portions including adouble-headed drum.

Furthermore, it is preferred that the rigid support end 18 be formed ata right angle or an acute angle with respect to the end wiring portion14 or the horizontal plane.

The foregoing descriptions of the specific exemplary embodiments of thepresent invention have been presented for the purposes of illustrationand description. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteachings. The exemplary embodiments were chosen and described in orderto explain certain principles of the invention and their practicalapplication, to thereby enable a person having ordinary skill in the artto make and utilize various exemplary embodiments of the presentinvention, as well as various alternatives and modifications thereof. Itis intended that the scope of the invention be defined by the Claimsappended hereto and their equivalents.

What is claimed is:
 1. A coil spring for a bed mattress having means forpreventing frictional noise which includes a body wiring portionsituated in a space between an upper edge member and a lower edgemember, and an end wiring portion provided on both ends of the bodywiring portion and set within a range in which the upper and lower edgemembers are disposed, and at least one of an upper exposed wiringportion extending from the end wiring portion so as to be exposed fromthe upper edge member and a lower exposed wiring portion extending fromthe end wiring portion so as to be exposed from the lower edge member,wherein at least one of contact wiring portions of the upper and lowerexposed wiring portions which abut to the end wiring portions while theupper and lower exposed wiring portion are being compressed has acontact surface which is in contact with one corresponding end wiringportion of the end wiring portions, whereby frictional noise between theexposed wiring portion and the end wiring portion is prevented.
 2. Acoil spring for a bed mattress having means for preventing frictionalnoise which includes a body wiring portion situated in a space betweenan upper edge member and a lower edge member, end wiring portionsprovided on both ends of the body wiring portion and set within a rangein which the upper and lower edge members are disposed, and at least oneof an upper exposed wiring portion extending from the end wiring portionso as to be exposed from the upper edge member and a lower exposedwiring portion extending from the end wiring portion so as to be exposedfrom the lower edge member, the coil spring further comprising at leastone rigid support end which is provided on the body wiring portion orthe upper or lower exposed wiring portion so as to absorb a compressiveload, wherein at least one of contact wiring portions of the upper andlower exposed wiring portions which abut to the end wiring portionswhile the upper and lower exposed wiring portions are being compressedhas a contact surface which is in contact with one corresponding endwiring portion of the end wiring portions, whereby frictional noisebetween the exposed wiring portion and the end wiring portion isprevented.
 3. The coil spring according to claim 3, wherein the rigidsupport end is formed at a right angle or an acute angle with respect tothe end wiring portion.